I'm not sure if it's better to reply here or in your thread, so I'll probably just do here so everyone can see.
The short version is that his elo rating (which you can't see, but is what determines the actual leaderboard position ) is higher ( not by much though. )
The easy to see version of this is his win % is higher than yours. He wins more of his matches than you do. Your elo will have gone up a fair amount when you beat him, but if you had lost, would have gone down a lesser amount. My guess without looking is that he just won games against a few more higher rated players than you.
You are obviously becoming better at the game, if you're playing people and constantly winning. If you won your next 6 games or so ( assuming they were all fairly highly ranked) , you would be around the same level as Guru
Note to future commentors, I'm not going to go into this deep of analysis for everyone.
come on, there are players which plays 30 games and are in top 50, if you really need just 30 games, this game make no sense anymore, if you find in this 30 games only newbies, you have a free win, really, the ladder system don´t works really.